Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5601f0aa99f9781…

MALICIOUS

PDF

85.9 KB Created: 2021-03-29 20:44:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 83c3f70c6f203abfbb763e7870a2e460 SHA-1: 95ec1684aef28fd46688213fe904c711fcb529be SHA-256: d5601f0aa99f9781201a9fe4ba50c49972d317d2a3f3bcf849715aa318a14002
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF file functions as a link farm, containing numerous external URLs pointing to other PDF documents hosted on various domains. The heuristic 'PDF_SEO_LINK_FARM' indicates a mass of external links, many on disposable hosting, suggesting a tactic to manipulate search engine results or distribute further malicious content. While no scripts were directly extracted, the nature of link farms often involves JavaScript for redirection or obfuscation, and the ML classifier strongly indicates malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://bologen.ru/award?keyword=effectiveness+definition+pdf PDF link annotation
    • http://all-system7.work/free_of_aiye_nsare3ovzi.pdfIn PDF document text
    • https://zixavuxo.weebly.com/uploads/1/3/1/3/131398386/fozov.pdfIn PDF document text
    • https://gikejujeg.weebly.com/uploads/1/3/5/9/135966421/pufetefu.pdfIn PDF document text
    • https://xilasofuvi.weebly.com/uploads/1/3/4/6/134651230/7fb23532a259fd.pdfIn PDF document text
    • http://amandeepsadyora.com/diccionario_biblico_hebreo_espaol_gratis_para_descargar56ucd.pdfIn PDF document text
    • http://eslivdrug.space/difference_between_platform_events_and_streaming_api9m8tc.pdfIn PDF document text
    • https://nobewiga.weebly.com/uploads/1/3/5/3/135315034/8b56b33457a68f.pdfIn PDF document text
    • https://fazijexin.weebly.com/uploads/1/3/2/7/132741066/31e485e7.pdfIn PDF document text
    • https://toginomaba.weebly.com/uploads/1/3/4/0/134042469/tanefinoz.pdfIn PDF document text
    • https://balukisivirunuw.weebly.com/uploads/1/3/5/3/135312861/vekuvuw.pdfIn PDF document text
    • https://wumigativagulam.weebly.com/uploads/1/3/1/6/131637174/54e44b.pdfIn PDF document text
    • http://vertigoa.online/lafudiguseja7mkvp.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://e8c82854-2a0b-4c0f-82de-bac600ce06e6.filesusr.com/ugd/d017d5_1dded792364e45519da0316741891edd.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/21e7c4c0-4ac7-490b-bbd7-bc08327c9130/tevolubuwakasovi.pdfIn PDF document text
    • https://777dd155-384c-4f1d-a337-8f27b94bb056.filesusr.com/ugd/1ecdae_c14dee396d3e4cdc9a2dde7f3c7326d5.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/23226442-f4f5-449e-ba59-e7d28e7c413a/what_is_the_importance_of_features_of_academic_writing.pdfIn PDF document text
    • https://a91873a8-1f5b-4151-915d-af39eb211f25.filesusr.com/ugd/3f80ec_67cb0a2183b6491a91453f9e812dbbd0.pdf?index=trueIn PDF document text
    • https://0879403c-3be5-48e4-925f-21334a7d5cfe.filesusr.com/ugd/407fcc_cab7fdf5cfdd47d59d78b11fb2e1b945.pdf?index=trueIn PDF document text
    • https://c2093f15-f4fb-4bda-9582-db5404103fa6.filesusr.com/ugd/b28561_d9243503febf4aa2a6d185ca6418e0ee.pdf?index=trueIn PDF document text
    • https://77da94c0-0f0a-445b-87af-e489a0b5ef66.filesusr.com/ugd/db1da1_f8b329dea8e34586a5879dd48178eb50.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/3da10815-6110-48f0-9cd3-f671c2b8d38e/thomas_merton_zitate_criminal_minds.pdfIn PDF document text
    • https://6d5fec37-5936-4ae8-8938-03a86e982f09.filesusr.com/ugd/d4da64_b591958c25ef474f8a7a9d0f8066860d.pdf?index=trueIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000112e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112E9 4828 bytes
SHA-256: ed53892eec7f65dfe54df59ed6cccd1f2624011e08c048e09b6aa975766ba12e
font_01_sfnt_off00012382.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12382 10896 bytes
SHA-256: c02795a9fbb0968314a68378fe353c4f19ea53c6b75b3f054bbd00eda4f0b44c